A water tank will be installed in the house for drinking water. It will be supplied by a truck. And I like to always know the water level in the tank. The only way so far is to open the tank lid and look inside.

Instead, I like to have a way to just look and see the water level from the outside. There are a few electronic gadgets in the market that have indicator lights for 25%, 50 %, 75%, and 100% full, but I want something with no electronic or electric components. Just caveman technology.

So, here is my question : are there any TRANSPARENT pipes to attach to the tank that can show the water level directly without any gadgeteering.

Thank you